1p0x: Difference between revisions

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-[[Image:1p0x.png|left|200px]]
+==F393Y mutant heme domain of flavocytochrome P450 BM3==
+<StructureSection load='1p0x' size='340' side='right' caption='[[1p0x]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
+== Structural highlights ==
+<table><tr><td colspan='2'>[[1p0x]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P0X OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1P0X FirstGlance]. <br>
+</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene><br>
+<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1jme|1jme]], [[1p0v|1p0v]], [[1p0w|1p0w]]</td></tr>
+<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CYP102A21 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1404 Bacillus megaterium])</td></tr>
+<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Unspecific_monooxygenase Unspecific monooxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.14.1 1.14.14.1] </span></td></tr>
+<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1p0x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1p0x OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1p0x RCSB], [http://www.ebi.ac.uk/pdbsum/1p0x PDBsum]</span></td></tr>
+<table>
+== Evolutionary Conservation ==
+[[Image:Consurf_key_small.gif|200px|right]]
+Check<jmol>
+  <jmolCheckbox>
+    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/p0/1p0x_consurf.spt"</scriptWhenChecked>
+    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
+    <text>to colour the structure by Evolutionary Conservation</text>
+  </jmolCheckbox>
+</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf].
+<div style="clear:both"></div>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+In flavocytochrome P450 BM3, there is a conserved phenylalanine residue at position 393 (Phe393), close to Cys400, the thiolate ligand to the heme. Substitution of Phe393 by Ala, His, Tyr, and Trp has allowed us to modulate the reduction potential of the heme, while retaining the structural integrity of the enzyme's active site. Substrate binding triggers electron transfer in P450 BM3 by inducing a shift from a low- to high-spin ferric heme and a 140 mV increase in the heme reduction potential. Kinetic analysis of the mutants indicated that the spin-state shift alone accelerates the rate of heme reduction (the rate determining step for overall catalysis) by 200-fold and that the concomitant shift in reduction potential is only responsible for a modest 2-fold rate enhancement. The second step in the P450 catalytic cycle involves binding of dioxygen to the ferrous heme. The stabilities of the oxy-ferrous complexes in the mutant enzymes were also analyzed using stopped-flow kinetics. These were found to be surprisingly stable, decaying to superoxide and ferric heme at rates of 0.01-0.5 s(-)(1). The stability of the oxy-ferrous complexes was greater for mutants with higher reduction potentials, which had lower catalytic turnover rates but faster heme reduction rates. The catalytic rate-determining step of these enzymes can no longer be the initial heme reduction event but is likely to be either reduction of the stabilized oxy-ferrous complex, i.e., the second flavin to heme electron transfer or a subsequent protonation event. Modulating the reduction potential of P450 BM3 appears to tune the two steps in opposite directions; the potential of the wild-type enzyme appears to be optimized to maximize the overall rate of turnover. The dependence of the visible absorption spectrum of the oxy-ferrous complex on the heme reduction potential is also discussed.
-{{STRUCTURE_1p0x|  PDB=1p0x  |  SCENE=  }}
+Oxygen activation and electron transfer in flavocytochrome P450 BM3.,Ost TW, Clark J, Mowat CG, Miles CS, Walkinshaw MD, Reid GA, Chapman SK, Daff S J Am Chem Soc. 2003 Dec 10;125(49):15010-20. PMID:14653735<ref>PMID:14653735</ref>
-===F393Y mutant heme domain of flavocytochrome P450 BM3===
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
+</div>
-{{ABSTRACT_PUBMED_14653735}}
-==About this Structure==
-[[1p0x]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacillus_megaterium Bacillus megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P0X OCA].
 ==See Also==
+*[[Cytochrome P450|Cytochrome P450]]
 *[[Flavocytochrome|Flavocytochrome]]
-*[[NADPH-Cytochrome P450 Reductase|NADPH-Cytochrome P450 Reductase]]
+== References ==
+<references/>
-==Reference==
+__TOC__
-<ref group="xtra">PMID:014653735</ref><references group="xtra"/>
+</StructureSection>
 [[Category: Bacillus megaterium]]
 [[Category: Unspecific monooxygenase]]